A new generation of carwash systems for effectively stripping rinse water from a vehicle passing therethrough is disclosed by U.S. Pat. No. 4,161,801 to Day et al. The apparatus includes a plenum supplying air under pressure and in communication with the open end of a flexible bag. Air is supplied through the bag to the nozzle of the bag which is in contact with the surface of the car to be stripped of water. The bag flexes at a hinge point to allow a vehicle to pass through the system. A problem arises either when the bag is so flexible that the nozzle does not contact the vehicle with sufficient force to effectively strip the water from the vehicle or when the bag is so rigid that it does not sufficiently flex at the hinge point to allow the vehicle to pass through the system. In the prior art systems, the bags are connected directly to the plenums and no means are provided for varying the resistance to hinging of the bags.